Running Lights Effect

fig 1:Running Lights effect

This is a simple but novel idea for achieving ‘running lights effect’. It is quite different from the electrical drum and contact system used for decorating buildings etc. It can be used commercially for attaining desired visual effects.
The circuit is built around CMOS IC CD4027, a dual J-K master-slave flip-flop, wherein all the outputs of the two flip flops i.e., Q1 and Q1, Q2 and Q2 are used. Variable speed clock pulses are obtained thro- ugh timer IC 555 and these are fed to the flip-flop through its clock input pin 13. The output of the top flip-flop (Q2) is used as clock input for the bottom flip-flop.
The flip-flops are edge-sensitive to the clock inputs and they change their states on positive-going transition of the clock pulses. Set and reset inputs of both the flip-flops are connected to ground while J and K inputs of the flip-flops are connected to the supply voltage.

It may be observed from the output waveform sequence shown in Fig. 3, that during each period of the IC 555 clock, two of the outputs remain high and these two outputs are used as inputs to one of the four AND gates.
During the first clock cycle the outputs Q1 and Q2 are high and both these outputs are connected to inputs of gate G1. During the second clock cycle outputs Q1 and Q2 are high and the same are connected to gate G2. Similarly, during third clock cycle the output Q1 and Q2 are high and they are taken as inputs for gate G3. During fourth clock cycle the outputs Q1 and Q2 are high and the same are fed to gate G4. This arrangement ensures that output of each AND gate goes high once in sequence during the first four cycles of the clock. It is also observed from Fig. 3 that the process repeats itself and the AND gates go high in the order G1, G2, G3, G4, and again G1, G2, G3, G4, and so on.
The output of each AND gate drives a transistor relay combination to drive heavy loads through their contacts. The loads may be either 6.3V AC, 115 mA bulbs or even 230V AC operated bulbs. The relay contacts and bulb arrangement are shown in Fig. 2.

fig: 2

The bulbs are so arranged as to give the desired running lights effect. The arrangement may be extended for the required number of bulbs beyond 16 bulbs in a similar fashion. The circuit operates continuously once the power supply is switched on.
We can also make use of four serial circuits consisting of 6.3V, 115mA bulbs operating on 230V AC mains, to achieve running lights effect, by arranging the first four bulbs for each serial set in the order B1, B2, B3, B4 and second four bulbs of each set arranged as B5, B6, B7, B8, and so on.

fig:3

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